Next best sparkplug?

[bve32k]

Ok. Here is what I have done. I have a 96 3.4L DOHC engine with the 60DegreeV6 Valve springs, retainers, light weight lifters, 8.5MM Magnecor Wires. I can't think of anything else, but I am sure I have more I should be putting up.

But I have tried the AcDelco RapidFire 6's and 12's. The 12's I went through within 2,000 miles. The engine was jumping around badly. I have been running the 6's for about 2,000 miles and now the engine is starting to jump around again.

Is there another plug I should try or is there something wrong?

Edit: The 12's I found out were gapped @ .060 and the 6's I have are gapped @ .045.

Here is a pic I took of the 12's. I haven't taken out the 6's yet. Top left one is piston #1 and bottom right one is piston #6. You guys catch the drift.

[pwmin]

how bout just getting some regular R42LTSM plugs and gapping them at 45?

[bve32k]

how bout just getting some regular R42LTSM plugs and gapping them at 45?

That was my next option. I just didn't do it yet because I wanted to get other peoples opinions first.

[z34phoenix]

the middle ones have the electrode burned away much more...

i would have your ICM checked and also test the resistances of all three coil packs... then make sure you use dielectric greese...

then i would check your grounds at the pcm and bat to frame.

something is causing the spark to be too hot. or there is a issue such as detonation that is destroying the tips.... if your ever in the daytona beach area let me know and i can give you a quick PCM tune, but deff get something to scan for KR... chances are you have some... i have noticed most of the plugs i have pulled from 96-97 DOHC's show lean.

[bve32k]

the middle ones have the electrode burned away much more...

i would have your ICM checked and also test the resistances of all three coil packs... then make sure you use dielectric greese...

then i would check your grounds at the pcm and bat to frame.

something is causing the spark to be too hot. or there is a issue such as detonation that is destroying the tips.... if your ever in the daytona beach area let me know and i can give you a quick PCM tune, but deff get something to scan for KR... chances are you have some... i have noticed most of the plugs i have pulled from 96-97 DOHC's show lean.

Thanks! But the computer is OBD1.5. Still have the 95 computer in my car. I checked the resistance on all the coils and I replaced the ICM. Everything seems normal.

[Rhedalert]

Does NGK Make something for your motor? They've been great in my Camaro (lot of LS1 guys use them) just the basic resistor plugs. I'm going to throw a set in my Olds too.

[HayesPerformance]

Stick to the factory plugs and make sure they are gaped perfectly the same.

I have tried other plugs and this engine Doesn't run well on too many others.

[HayesPerformance]

Oh ya,

DO NOT INSTALL THE BOSCH PLATINUMS IN YOUR GM ENGINE!!!

[RedZMonte]

Stock delco's or NGKs will both be good plugs.

[pwmin]

i would just try some stockers and see if the problem is still there. theyre cheap enough to replace. may just be a problem with the platinum. btw, i have 5 decent used 12s you can have if you want them.

[bve32k]

I had 12's. But my engine seemed to have gone through them pretty fast. So I don't think I will be going back to them soon. I think I am going to try stockers or NGK. Not sure yet.

[torq455]

how hot of a plug are the 6 and 12's? too hot of a heat range can melt the plugs.

[bve32k]

I believe the 6's are cooler plug than the 12's. IIRC.

I haven't taken the 6's out yet. But I am about to switch to the standard copper core plugs. To see if they run better.

[HayesPerformance]

The A/C plug for the 3.4 dohc is ACR42LTSM

In my GM Catalog when broken down means the following;

"A" - Clip style gap
"C" - Copper Core Center Electrode
"4" - 1st number denotes THREAD SIZE 4 = 14mm with 1/2" tapper
"2" - 2nd number denotes HEAT RANGE
COLD ------------- HOT
0-1-2-3-4-5-6-7-8-9
"L" - Long Reach
"T" - Tapered Seat Shell Design
"S" - Sport Vehicle (Only on 3.4 dohc)
"M" - Specially Designed Electrode

[garylau]

Oh ya,

DO NOT INSTALL THE BOSCH PLATINUMS IN YOUR GM ENGINE!!!

Just curious, why is that? I think I recall using them a couple times.